[skip ci] Add more suggested links

iluuu1994 · iluuu1994 · commit 6e5f4aad8884 · 2023-04-28T13:49:03.000+02:00
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
@@ -96,6 +96,8 @@ base.
 * https://www.phpinternalsbook.com/
 * https://www.npopov.com/
 * https://wiki.php.net/internals
+* https://qa.php.net/phpt_details.php
+* https://phpinternals.net/
 * https://blog.ircmaxell.com/categories/PHP/
 
 ## Writing tests
